import java.sql.*;
import java.util.Scanner;
public class Main{
    public static void main(String[] args) {
      //m1();
        //m2();
        //m3();
        m4();
        m5();
    }

    private static void m2() {
    // 1、加载驱动
    try {

        // Scanner
        Scanner sc = new Scanner(System.in);
        System.out.print("请输入你要查询的姓名：");
        String word = sc.next();

        Class.forName("com.mysql.cj.jdbc.Driver");

        // 2、获取连接 (url username password)
        String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
        Connection connection = DriverManager.getConnection(url, "root", "20080808a");
    //            if (connection != null) {
    //                System.out.println("连接成功");
    //            }
        // 3、写sql
        String sql = "select * from sys_user where name like ? ";

        // 4、预编译sql
        PreparedStatement preparedStatement = connection.prepareStatement(sql);

        // 5、有参数设置参数
        preparedStatement.setObject(1,"%"+word+"%");

        // 6、执行sql
        ResultSet resultSet = preparedStatement.executeQuery();

        // 7、遍历结果集
        while (resultSet.next()){
            int id = resultSet.getInt(1);
            String name = resultSet.getString(2);
            String pass = resultSet.getString(3);
            System.out.println(id+"-----"+name+"------"+pass);
        }

        // 8、关闭资源
        resultSet.close();
        preparedStatement.close();
        connection.close();


    } catch (ClassNotFoundException e) {
        throw new RuntimeException(e);
    } catch (SQLException e) {
        throw new RuntimeException(e);
    }
}
    private static void m3() {
        // 1、加载驱动
        try {

            // Scanner
            Scanner sc = new Scanner(System.in);
            System.out.print("请输入要新增的姓名：");
            String name = sc.next();
            System.out.print("请输入要新增的密码：");
            String pass = sc.next();

            Class.forName("com.mysql.cj.jdbc.Driver");

            // 2、获取连接 (url username password)
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            Connection connection = DriverManager.getConnection(url, "root", "20080808a");
//            if (connection != null) {
//                System.out.println("连接成功");
//            }
            // 3、写sql
            String sql = "insert into sys_user(name,pass) values (?,?) ";

            // 4、预编译sql
            PreparedStatement preparedStatement = connection.prepareStatement(sql);

            // 5、有参数设置参数
            preparedStatement.setObject(1,name);
            preparedStatement.setObject(2,pass);

            // 6、执行sql  executeUpdate
            int result = preparedStatement.executeUpdate();

            // 7、结果判断
            if (result > 0) {
                System.out.println("新增成功");
            }

            // 8、关闭资源
            preparedStatement.close();
            connection.close();


        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
    private static void m1() {
        // 1、加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");

            // 2、获取连接 (url username password)
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            // .var
            Connection connection = DriverManager.getConnection(url, "root", "20080808a");
//            if (connection != null) {
//                System.out.println("连接成功");
//            }
            // 3、写sql
            String sql = "select * from sys_user";

            // 4、预编译sql
            PreparedStatement preparedStatement = connection.prepareStatement(sql);

            // 5、有参数设置参数

            // 6、执行sql
            ResultSet resultSet = preparedStatement.executeQuery();

            // 7、遍历结果集
            while (resultSet.next()){
                int id = resultSet.getInt(1);
                String name = resultSet.getString(2);
                String pass = resultSet.getString(3);
                System.out.println(id+"-----"+name+"------"+pass);
            }

            // 8、关闭资源
            resultSet.close();
            preparedStatement.close();
            connection.close();


        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
}
    private static void m4(){

        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            Connection connection = DriverManager.getConnection(url, "root", "20080808a");
            String sql = "update sys_user set name=?,pass=? where id=?";
            PreparedStatement preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setString(1,"王小明");
            preparedStatement.setString(2,"888");
            preparedStatement.setObject(3,"9");
            int result = preparedStatement.executeUpdate();
            if (result > 0) {
                System.out.println("修改成功");
            }
            preparedStatement.close();
            connection.close();


        } catch (SQLException e) {
            throw new RuntimeException(e);
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        }
    }
    private static void m5() {
        // 1、加载驱动
        try {

            Class.forName("com.mysql.cj.jdbc.Driver");

            // 2、获取连接 (url username password)
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            Connection connection = DriverManager.getConnection(url, "root", "20080808a");
//            if (connection != null) {
//                System.out.println("连接成功");
//            }
            // 3、写sql
            String sql = "delete from sys_user where id = ? ";

            // 4、预编译sql
            PreparedStatement preparedStatement = connection.prepareStatement(sql);

            // 5、有参数设置参数
            preparedStatement.setObject(1,"7");

            // 6、执行sql  executeUpdate
            int result = preparedStatement.executeUpdate();

            // 7、结果判断
            if (result > 0) {
                System.out.println("删除成功");
            }else System.out.println("删除失败");

            // 8、关闭资源
            preparedStatement.close();
            connection.close();


        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
}
